Bullous Pemphigoid Associated with Acquired Hemophilia A: A Rare Association of Autoimmune Disease

Background: Acquired hemophilia (AH) is a rare autoimmune disease with an annual incidence of one per million and has a mortality rate of up to 22%. It is caused by the development of autoantibodies against factor VIII. Approximately half of the reported cases are associated with autoimmune disorders, pregnancy, malignancies, and adverse drug reactions. Autoimmune diseases are the most frequently associated disorders and include rheumatoid arthritis, systemic lupus erythematosus, cryoglobulinemia, pemphigus vulgaris, and bullous pemphigoid. There are a few reports of acquired hemophilia and bullous pemphigoid in the literature. Method: We report a 73-year-old male who presented with cutaneous blistering, upper gastrointestinal bleeding, and hemoptysis. He later developed right flank pain secondary to a retroperitoneal hematoma. He had a prolonged partial thromboplastin time, a low factor VIII level, and a high factor VIII inhibitor level, all consistent with acquired hemophilia. Skin biopsies were diagnostic for bullous pemphigoid. Results: He was treated successfully with prednisone, cyclophosphamide, rituximab, and intravenous immunoglobulin.